Elevator-controlling apparatus.



W. BAXTER,-Jn. ELEVATOR CONTROLLING APPARATUS.

APPLIOA'IIOH FILED AUG-.4. $905.

Patented Dec. 17, 1912.

' witnessed UNITED STATES PATENT onrrcn- WILLIAM BAXTEB, J 3., OF J EBSEY CITY, NEW JERSEY, ASSIGNOR TO OTIS ELEVATOR COMPANY, A CORPORATION OF NEW JERSEY.

ELEVATOR-CONTROLLING APPARATUS. I

Specification of Letters Patent.- Application filed August 4, 1905. Serial No. 272,654.

Patented Dec. 17, 1912,

' sion of means for reducing to a minimum the formatlon of electric arcs upon the breaking of the various circuits in a motor controlling system.

A further object'of the invention is to provide an improved and efficient means for slowing down the motor before stopping.

Another object is to provide efiicient means for stopping the-motor gradually.

Other objects of the invention will appear hereinafter, the novel combinations of elements being set forth in the claims appended to the following description.

In the accompanying drawings, Figure 1 represents diagrammatically my invention I applied to a single push-button controlled electric elevator system; Figs. 2 and 3 are detail views of the floor controller; and Fig. 4 is a modification of the brakemagnetcircuits.

1 designates the elevator car which is connected to the hoisting mechanism in a wellknown manner, the hoisting mechanism being driven by an electric motor of which 2 represents the armature, 3 the shunt field,

I 4 the series field and 5 the extra field. The

usual starting resistances 6 and accelerating magnet 7 are connected in a suitable manner a to the motor circuits so that the motor may start and gradually run up to \full speed after either the up or down relay, designated U and .D. respectively, has been operated. By the closing of one of the hall buttons 9, 10, 11 or 12 or of the car buttons 9',

15, 16, 17 or 18 and thence to the floor controller 19 which is positively connected to some moving part of the hoisting mechanism so that the car shall stop automaticall The floor cdntroller 19 comprises a revolu= ble screw-threaded shaft 21 mounted in suitable bearings in the brackets 22 and 23. Between these brackets and onthe shaft is a nut 20 which is moved along the shaft 21 with a speed proportional to the speed of the car. Through a slot in one side of the nut passes ,a rod 25 which is secured at its ends to the brackets 22, 23, this rod serving as a guide for the nut 20 and preventing the same from turning. On the other side of the nut 20 is a projection or striker-24 which is adapted to engage the shoulders 26 of levers 27 28, 29 and 30 which are pivoted, respectively, at 31, 32, 33 and 34. The

inner ends of these levers are shown forked to form the shoulders 26 'while to the outer ends are connected the circuit closers 35,36, 37 and 38, the circuit closers being insulated from the levers by intervening pieces of insulation 39, 40, 41 and 42, respectively.

Suitable sto s 43 are provided for limiting the throw 0 these levers and circuit closers. The circuit closers are adapted to move over a plurality of contact blocks which may be made adjustable. hese contact blocks are arc-shaped and pre erably made adjustable in arc with relation to the circuit closers so that the circuit closers will begin to engage thevsame at any time desired. One form of adjusting means is shown in Figs. 2 and 3 wherein one of the contact blocks or strips,

as 45, is provided with integral projections 46, 47 through which bolts 53, 49 are passed and wing nuts 54, 55 used for clamping the are 45 at any point within the limits of the slots 51, 52 to a suitable base 48 of insulating material.

It is seen that the station limit switches for-the top and bottom floors or landings 'are each single while the intermediate ones are double. The distances between them are proportional to the distances between floors. Within certain limits, if, the distances between floors vary 'the arc-shaped contacts that the car .will stop substantially 'level with the floor.

The operation of the system thus far described is as follows :-Assuming that the to and through the wire 64, door contacts 65, 110

may be moved and clampedin position so car is at the lowermost landing and the nut wire 66, car buttons 67, wire-68, safety pushbutton 69, wire 70, contact plates 71, 72, 73

, and 74 and their lower fixed contacts, wire 75,,hall push-button 12, wires 76, solenoid 92of relay 18, wire 93, magnet 56, of one of the auxiliary relays, are contact-strip 44, circuit closer 35 contact-strip -78, wire 79, up magnet U wire 80, wire 81, adjustable resistance 82, to point 94 where the circuit divides, part going through the brake magnet 83 and wire 90 and part through wire 84, contact 85, wire 95, fixed contact 86, lever 87, and resistance 89, whence the circuit continues through the wire 91 to the main, 14. The magnets 92 56 and U will .thereupon be energized. The solenoid core 95' will be drawn up with its circuit closer 74 to form a retaining circuit for the magnet 92 through the contacts 96, 97 between the conductor 70 whichis coimnon to the hall and car push-buttons and the conductor 76 which is individual to the "relay 18 and the top push-buttons. Circuit to the contacts of the relays 15, 16 and 17 is broken also, so that interference from any hall or car button is prevented until after the car is stopped and the hall door opened to open the top switch 65. The magnet 56 draws up its armature 60 but this operation has no eflrectuntil the car. approaches the top floor landing." The magnet U draws its core to the left to operate the up reversing switch. The current through the brake magnet is too small to eflect the release of the brake, the

resistance 89 which is preferably equal to the brake magnet resistance being in parallel to the brake magnet and the resistance 82, which is substantially equal to the resistance of the magnet U, being in series with it.-

It .will be noticed that when the floor con- I trolling main magnet 92 operates to lift the contact maker 74 it connects the contacts 96,

97 before it disconnects thecontacts 98, 99.

This is necessary in order to prevent arcing at the contacts 98, 99 and is accomplished by having the contacts 96, 97, 98 and 99 secured to the inner ends of the springs 171, 172,

173 and 174, respectively, which springs tend to move the contacts 96, 97 toward the contacts 98, 99 but are limited in their movement bythe fixed intermediate blocks of insulation 169, 17 0. Normally the contact maker 74 rests'on the contacts 98, 99, bend- 56 ing the springs 173, 174 as shown in full lines and the springs 171 and 172 rest on the upper sides of the insulating blocks 169, 170. It is obvious that the parts may easily be so adjusted that the contact maker 74 will con 00 nect the contacts 96, 97 a moment before it leaves the contacts 98, 99 so as not to inter- 'ru t a circuit having inductance in it.

on either the up or down magnet operates to move its core 100 or 136 to the left or 85 right, it does so against the action of the centering spring 103 or 104 which are fixed to the base 105. These springs normally bear againstithe lateral pin 102 on the rod 164 which joins the cores 100 and 136. Just tothe right of the spring 104 is a downwardly extending arm 107 rig d with the rod 164 and'pivoted at its lower end to the link 108. This link is pivoted at its right- "hand end to an intermediate point on the lever 87 which is pivoted at a fixed point 18. This lever is adapted to act as a circuit closer to connect together either the contacts 133, 134 or 137, 85.

The lateral pins 101 and 131 are adapted to engage forks 130 and 132, respectively, which are secured to circuit closing levers 1 20 ,and- 125 which are pivoted at 138 and lated fixed contacts 117, 119, 11s and 122,

124, 123, respectively. Each of the long levers '120, 125 is provided with a lateral pin 111 and 126 adapted to engage the V-shaped levers to move the same in one direction or the other so that their arms shall engage the contacts 115, 116, 139 and 140.

3 It will be noticed that the reversing switche's'are insulated from each other by' means of the insulating section 106' in the 'rod which connects the cores 100 and 136.

Insulation 162 electrically separates the long lev'er 120 from the arms 114 and 112 but the latter are always in engagement with fixed contact strip 113. Furthermore, a section of insulation 109, insulates the switch mechanism for the brake magnet from the I down reversing switch.

'When the magnet U is energized as hereinbefore explained, the pin 101, being in engagement with the fork 130 will move the tact 118. At the same time-the pin 111 en gages the arm 112 to move the same onto the contact 116. The pin 131, by means of the fork 132, effects a movement of the lever 125 to the contact 123 and the pin 126 moves the arm 127 onto the contact 140. At this time also the lever 87 is moved to the left to connect the contacts 133, 134, whereupon the resistances 82 will be short-circuited, the

lever from the contact 119 to the concircuit through the brake magnet then being through the contacts 133, 134, lever 87,

wire 95, contact 85 and wire 84. Suflicient current can now pass to eiiect the releasing of the brake. Substantially at the same time the circuits to the motor are closed and the motor may staitThe motor circuitsmay be traced as follows: fromthe main 13 to and throu h the contact 118, lever 120, wires 141 and 142, starting res1stance6,

therewith, contact 116, motor -armature 2,

wire 143, contact 140, arm 127, lever 125,

contact 123, tothe main, 14. A circuitis also closed through the shunt field 3 by means of the wires 144, 145., In a wellknown manner the resistances 6 and the series field 4 are cut out step-by-step means of the accelerating magnet 7 WhlChlS connected across the motor-armature at the points 147 and 146. The motor having thus been started will continue to move the car and consequently the floor controller until the striker 24 engages the fork 150 of the lever 27 and moves-the same to effect a gradual stopping of the car. At a short time before the car reaches the top floor the circuit closer 35 will engage the contact 45 besides the contacts 44' ancl 78; the lever 27 and circuit closer 35 will then assume the position indicated in dottedlines 151. A circuit will now be closed from contact strip 44 through circuit closer 35 and strip 45 to and through switch 60 of the auxiliary relay, thence by wire 152 to wire 80, brake magnet 83, and to the negative; line. The up magnet U will therefore be short-cir cuited and the spring 104 will restore ,the reversing switches to normal position. When the reversing switches are thus restored, however, the brake ma et circuit is interrupted at the contacts 133, 134 and the selfinduction discharge or kick will tend to produce sparking or arcing and burn up the contacts and circuit closer 87. But this discharge is taken up in the local circuit including the resistance 89 and the brake magnet 83 in series. It will be noticed that the resistance 82 is again placed in series with the brake magnet but now the up magnet U is short -circuited. The resistance 82 is primarily for the purpose-of compensating for the resistance of the up magnet U so that too much current will not flow through said brake magnet when the circuit closer 35- engages the strip 45. The resistance 82 is preferably equal to that of the up magnet. It is evident that the "current passing through the brake-magnet 'at this time may be such as toonly partially release the brake. This may be better accomplished by having the resistances 89 and 82 adjustable, as shown. 1' s In Fig. 4 I have shown a modification of the brakemagnet circuits .inthat the shunt resistance 891s cut out when the magnet is energized to lift the brake. This is accomplished by providinga fixed pivot 165 for the lever 87 and having arc-shaped contact strips 167 and 95' for the arms'166 and 167 respectively, of the lever 87 to come in contact with. *With this arrangement when the reversing switches areo erated in either direction the arm 168 which is always in engagement with the strip 9-5 will engage either the fixed contact 133 or the fixed contact 135 and the arm 166 will leave the contact 167. Preferably the arm 168 engages either of the contacts 133 or 135' before the arm 166 leaves the contact block 167 so that when the lever 87 is restored to normal position the resistance 89 will be connected in a local circuit before the resistance 82 is connected in series with the brake magnet. It is deemed an advantage to have the resist ance 89 cut out during the operation of the motor so as to lessen the consumption of current but in' some cases it may be desirable to shunt. part of the current away from thebrake magnet to prevent overheating of its. coils.

It should be noted that the slow down magnet 153 is connected in circuit with the motor when the levers 120 and 125 are restored to normal position'and engage the contacts 119 and 124. The motor will now act as a generator to send current through local circuits, this arrangement constituting an electro-dynamic brake, the braking effect being proportional'to the load so that the car shall stop substantially level with the floor landing irrespective of the load. The first step in slowing down kthe motor may be the partial application of the brake. Preferably, however, the first step is the breakin of the main line circuits by the restoration of the levers 120 and 125 to normalposition. The slow down magnet 153 will then be connected across the motor magnet .may be traced from brush 148, through wire 156, contact 116, arm 112, strip 113, wire 157, wire 170, contact 175,- switch 176, wire 177,. wires 142 and 141, lever 120,

contact 119, wire 155, slow-down magnet ;153, wire 154, contact 124, lever 125, arm

127, contact 140, wire 143, to the other brush 149. The shunt field 3 is connected between the points 158 and 159 in parallel 1 wire 145, extra field coil 5, sectional re-1 sistance 160, wire 157, strip 113, arm 112, contact 116, wire 156, to brush 148' This circuit through the extra field 5 and res'istance 160 is established whenever the -reversing switch has been operated, so that 55 ture to drop, thus interrupting the circuit.

the extra field and the resistance 160 are in series with the motor armature when the latter is running at normal speed. When the reversing switch magnet is deenergized and the switch levers 120 and 125 are brought back to central position a circuit is established through the slow down magnet 153, so that more or ,less of the resistance 160 will be short-circuited in the well-known manner by the slow-down magnet as the motor comes to rest, the amount of resist-' ance cut out and the rate of cutting out depending upon the speed of the motor.

The effect of cutting out this resistance is to strengthen the extra field 5 and increase. the armature current and therefore increase the electro-dynamic braking effect.

It should. be noted that the reversing switches serve a double function in that the slow-down apparatus is controlled by them as well as the starting means. This I consider a valuable feature of my invention, so also the means for preventing the formation of arcs. It will also be noticed that when a reversing switch magnet is 'short-' circuited it is placed in a local circuit so that its discharge of self-induction may take place without any arcing as by the breaking of a circuit containing the reversin switch. This local circuit may be traced rom the magnet U, for example, as the source of the electro-motive-force of self-induction through the wire 152, switch 60, strip 45, circuit-closer 35, wire 79, back to the magnet.

,As the car approaches more" nearly to its floor or landing and has been slowed down to almost a stop the circuit closer 35 en gages the strip 46 and leaves the strip 78.

The circuit closer 35 then assumes the position indicated by the dotted lines 163. The removal of the circuit closer 35 from' the strip 78 will produce no arcing as the mag-. net U has already been deenergized and its short-circuit isstill closed through the contact strip 45. When 'the circuit closer 35 engages the strip 46,'however, the floor relay magnet 92 and the auxiliary floor relay magnet 56 will be short-circuited by the wire '77, whereupon the magnets. 92 and 56 will be deenergized but there can be no formation of any arcs as their self-induction ourrent is consumed in a local circuit through the wires 93 and 77, contacts 44 and 46, and both magnets in series. The deenergization of magnet 56 will cause its armato the brake magnet and effecting the full applicationjof the brake and the absolute stopping of the car. The deenergization of the magnet 92 will cause its contact maker 74 to drop to restore the controlling circuits to normal so that by pressing one of the lower hall buttons or one of the car but-- tonscorresponding thereto exclusive control of the car may again bsobtained call-the car to a particular -floor.or send the car to that floor.

Without limiting myself to the details of construction or arrangement of parts, what motor, of motor-controlling means including reversing switchmagnets, a series of main relays corresponding to the floors of a building, push buttons and circuits connected to said relays, auxiliary relays in circuit with said main relays, means coacting with said' auxiliary relays for short-circuitmg said reversing switch magnets, and 1a short-circuit for the main and auxiliary relay magnets arranged to be closed by the aforesaid shortcircuiting means. Y i

3. The combination with a car and its motor, of motor-controlling apparatus including reversing switch magnets, a series of main relays corresponding to the floors of a building, push-buttons in circuits concuit with said main lays, stop-motion lim t switches for automa ically and successively short-circuiting the reversing switch magnets, the main relay magnets, and said auxiliary magnets, to effect the restoration of the switches in circuit with said magnets to normal position without arcing.

- '4. The combination with a motor, of

nectedto said relaysxifauxiliary relays in cirmotor-controlling means including reversing switch magnets, means for short-circuiting said reversing switch magnets, a brake magnet connected in' circuit with said reversing switch magnets, -a resistance, and means for connecting said resistance in circuit with 7 said brake-magnet to compensate for the short-circuited reversing switch magnet,

5. The combination with a motor, of

elebtromagnetic reversing switches therefor,

a brake magnet in circuit with the reversing switch magnets, means for short-circuiting said reversing switch magnets, two resistances, means for connecting'one of said recompensate for the short-circuited reversing switch ma ct and for connecting the other resistance in a localcircuit with said brake magnet.

6'.' The combination with a motor, of reversing switch'mechanism therefor, electromagnets for operating said reversing switches, a brake magnet, a resistance, and a sistances in circuit with the'brake magnet to magnets for connecting said resistance in a local circuit with said brake magnet.

7. The combination with a motor, of controlling means, a brake magnet, two'resist-- ances, and means co-actmg with said controlling means for connectin one of said resistances in series with the rake magnet and the other in shunt thereto.

'8. The combination with a motor, of motor-controlling means, a brake, magnet, a resistance normally, in series with the brake-magnet, an additional resistance in shunt to the brake-magnet, and means 30-, tuated upon the operation of one of the reversing switches for short-'circuiting said first-named resistance.

9. The combination with a motor, of re-' versin switches therefor electroma ets .for operating said reversing switches, a

brake magnet, resistances in circuit with the brake magnet, means operated by said electromagnets for short-circuitlng one of said resistances, and means efl'ecting a centering of the last-named means and of the reversilig switches upon the deenergization vof the electromagnet last operated.

In testimony whereof, I have signed my name to this specification in the presence of two subscribinrr witnesses.

. WILLIAM BAXTER, JR. Witnesses:

FRANK T. BROWN,

CHARLES M.'NISSEN. 

